1. Technical Field
The present invention relates to a printing control device and a printing control method.
2. Related Art
Ink jet printers, for example, dots are formed on print substrates by relatively moving the print substrates and nozzle lines in which a plurality of nozzles are arranged in a predetermined nozzle line direction in relative movement directions intersecting the nozzle arrangement directions and ejecting ink droplets (liquid droplets) from the nozzles according to nozzle data that indicates presence or absence of an ink dot for each pixel. Ink jet printers in which main scanning and sub-scanning are repeated include, for example, serial printers in which high-speed printing such as band printing is performed and serial printers in which pseudo-band printing is performed. Here, the band printing is a printing scheme of forming all of the dots of a band having a length corresponding to a one-time feed amount (also referred to as a transport amount) of a print substrate in a sub-scanning direction through one-time main scanning. The pseudo-band printing is a printing scheme of forming all of the dots of a band, which is a unit in which all of the dots are formed in a sub-scanning direction, through M-time main scanning (where M is an integer equal to or greater than 2). Sub-scanning between main scanning at the time of formation of dots of equal bands is a feed amount corresponding to 1/M of a pitch of nozzles in a sub-scanning direction.
There is a possibility of banding (stripes formed in a main scanning direction) occurring in boundaries of bands due to a transport error of a print substrate or a landing error of dots between the bands. To reduce the banding, partial overlap printing is performed in which print regions, where print images are formed at the time of main scanning performed before and after sub-scanning of a distance longer than a pitch of nozzles in a sub-scanning direction, are partially overlapped. In the partial overlap printing, recording of the overlapped overlap regions is divided into main scanning before the sub-scanning and main scanning after the sub-scanning. The number of nozzles recording the overlap regions among the nozzles included in nozzle lines is not changed irrespective of the number of times the main scanning is performed.
JP-A-2014-113708 discloses an image forming apparatus that includes an ink jet recording head. In the image forming apparatus, all of the nozzles of a link portion in which the end of a recording head overlaps at the time of scanning performed so that the end of the recording head overlaps are used and the sizes of ink droplets in the link portion are set to be smaller than the sizes of ink droplets in a portion other than the link portion so that an image density of the link portion is not changed. The number of nozzles included in the link portion among the nozzles included in the recording head is not changed irrespective of the number of times the main scanning is performed.
In the image forming apparatus, it is necessary to change the sizes of the ink droplets in order to form an image including the link portion and there is a possibility of banding being viewed due to a difference in the sense of granularity of ink dots between the link portion and a non-link portion depending on a print substrate. On the other hand, it is suitable that a printing speed can be improved.
The foregoing problems similarly occur in various apparatuses.